1. Field of the Invention
This invention relates to the printing art.
2. Brief Description of the Prior Art
The following patents are made of record: U.S. Pat. Nos. 3,955,711; 4,407,692; 4,776,714; U.S. Pat. No. 4,956,045; U.S. Pat. Nos. 4,957,379; 5,267,800 and European patent application 0 449 236.